trail calls in the paint

[rsl]

This is motivated by the "To reach or not reach" thread, but it is really different.

In NFHS two man, what are trail's responsibilities in the paint?

At a recent camp I had the following situation. A1 throws a lob pass to A2 in the lane, and A2 has inside position on B2. A2 and B2 are standing five feet away from lead. As trail, I close to almost foul line extended because all the of the action is in the paint. I see a B2 foul A2 on lead's blind side, with significant contact but not a train wreck. I wait, there is no call from lead, so I whistle.

At the next break, lead (an experienced ref on our local board) tells me he saw the contact but was waiting for the shot, which A1 was certainly going to take any second. He then told me never whistle something right in front of your partner. Good advice.

I thought I had been taught that trail should watch for backside contact when the ball goes in the paint or on rebounds. But I think I reached on this one when I shouldn't have.

When is trail supposed to put two sets of eyes on the key? Never?